2.7.11.1. About Durbin Creek
- East of the St. Johns River
South of I-295- Primary Land Use: Forested
- Current TMDL reports:
Fecal Coliform, Mercury - Not included in 2020 Verified List of Impaired Waters
- WBID Area: 26.2 sq. mi.
-
Beneficial Use: Class III F
(Recreational – Freshwater)
2.7.11.2. Data sources
Result data were downloaded from the FL STORET and WIN websites (DEP 2010f; DEP 2018) and filtered based on the stations (DEP 2010g) in the Durbin Creek WBID 2365 (DEP 2014c) shown above. The filtered dataset reflects water column concentrations and was used to generate Table 2.14.
2.7.11.3. Discussion
Water quality data for Durbin Creek are shown in Table 2.14. Historically, average dissolved oxygen levels in Durbin Creek were relatively low when compared to other tributaries of the LSJRB. However, no causative pollutant (specific environmental condition) has been identified, and thus no TMDL report is required as it is the “natural condition” of the water body (DEP 2009c). Average dissolved oxygen concentrations were above the WQC from 2019 to 2021. A TMDL report is available for fecal coliform in Durbin Creek (Magley 2006a), but average fecal indicator bacteria levels in Durbin Creek were lower than the WQC in 2019, 2020, and 2021. (Note: the data analyses in the TMDL are based on different criteria than that used in this report). The concentrations of several heavy metals jumped in 2018 and 2019 compared to previous years, although the average concentrations remain lower than the corresponding WQCs. The average copper concentration nearly tripled between 2018 and 2020. In 2021, average concentrations of arsenic, cadmium, nickel, and silver fell compared to 2019 and 2020, while the average concentration of lead increased.
Historical water quality data for Durbin Creek are available in previous versions of the River Report.
Table 2.14 Water quality data for Durbin Creek.
| Water Quality | Average and Number of Samples º | |||
|---|---|---|---|---|
| Parameter | Criteria (FW) | 2019 | 2020 | 2021 |
| Dissolved Oxygen (mg/L) | ≥34% sat. (≥3.0) | 5.24 (0 of 8 samples) | 5.81 (2 of 10 samples) | 6.15 (0 of 11 samples) |
| Total Nitrogen (mg/L) | <1.54‡ | 0.88 (0 of 3 samples) | Not available | Not available |
| Total Phosphorus (mg/L) | <0.12‡ | 0.06 (0 of 4 samples) | 0.08 (1 of 5 samples) | 0.08 (1 of 6 samples) |
| Chlorophyll-a (µg/L) | <20‡ | 1.00 (0 of 3 samples) | 0.08 (0 of 5 samples) | 1.00 (0 of 3 samples) |
| Arsenic (µg/L) | ≤50 | 1.92 (0 of 3 samples) | 0.75 (0 of 5 samples) | 0.25 (0 of 3 samples) |
| Cadmium (µg/L) | ≤0.3 | 0.28 (0 of 2 samples) | 0.08 (0 of 5 samples) | 0.03 (0 of 3 samples) |
| Copper (µg/L) | ≤9.3 | 5.25 (1 of 3 samples) | 7.25 (1 of 5 samples) | 5.52 (1 of 3 samples) |
| Lead (µg/L) | ≤3.2 | 0.28 (0 of 2 samples) | 0.28 (0 of 5 samples) | 0.49 (0 of 3 samples) |
| Nickel (µg/L) | ≤52 | 2.75 (0 of 3 samples) | 2.25 (0 of 5 samples) | 1.08 (0 of 3 samples) |
| Silver (µg/L) | ≤0.07 | 0.11 (1 of 3 samples) | 0.03 (0 of 5 samples) | 0.03 (0 of 3 samples) |
| Zinc (µg/L) | ≤120 | 19.17 (0 of 3 samples) | 17.5 (0 of 5 samples) | 19.17 (0 of 3 samples) |
| Fecal Indicator Bacteria (E. coli) (CFU/100 mL) | <410 | 85 (0 of 5 samples) | 120 (0 of 6 samples) | 120 (0 of 8 samples) |
| Turbidity (NTU) | <29 | 2.38 (0 of 3 samples) | 5.73 (0 of 5 samples) | 12.49 (0 of 3 samples) |
